Hot Water Cylinder Thermostat problem - I’ve been stupid.

[SnakeDoctor]

I have: -
Gas combined central heating and water heating
Drayton MA1 Mid Position Actuator
Drayton HTS3 Cylinder Thermostat
Solar iBoost+ that’s connected to 2 Immersion Heaters (top and bottom)

I wanted to replace the HTS3 with one that has a lower lowest setting so that the solar immersions heat my water to about 80 leaving the gas as backup at a lower temperature. I bought a Horstmann HCT1 and thought that I’d connected the 3 wires correctly but I obviously got it wrong because the water heating was on when it should have been off and vice versa.
I then decided to go back to the HTS3 and start again. That was when I realised that I had forgotten to write down which wire went to which terminal (what an idiot). I guessed at: -

Terminal 1 – Brown
Terminal 2 – Blue
Terminal C – Black

What I have now is: -

When the Water Heating control is OFF - Terminal 2 is LIVE and 1 and C are NOT LIVE

When the Water Heating Control is ON and the Thermostat Temperature is set to 50 – Terminal 2 is NOT LIVE and both Terminal C and Terminal 1 are LIVE

When the Water Heating Control is ON and the Thermostat Temperature is set to 80 – Terminal 2 is NOT LIVE and both Terminal C and Terminal 1 are LIVE

Is this correct? It’s difficult for me to tell because Solar has used the Immersion Heaters to heat the water to about 80.

Please can anyone help me?

 

[tamz]

Unfortunately colours don't mean much on a stat cable.

You will need to find the junction box for the heating (it will probably be near the motorised valve) and have a look at what colour wires connect to what.

The wire that connects to the orange of the motorised valve should go to 1 on the stat
The wire that connects to the grey of the motorised valve should go to 2 on the stat
The remaining wire goes to C.

Take the stat off the tank while you try turning it up and down and the heat won't affect its switching

 

[SnakeDoctor]

Many thanks tamz. Just what I needed. All working now with the new thermostat.